diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index 41f3eff772f..aa5381d3fb7 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -5,7 +5,7 @@
 <%! from data import Keyword, to_rust_ident, to_camel_case, LOGICAL_SIDES, PHYSICAL_SIDES, LOGICAL_SIZES %>
 
 <%def name="predefined_type(name, type, initial_value, parse_method='parse',
-            needs_context=True, vector=False, **kwargs)">
+            needs_context=True, vector=False, initial_specified_value=None, **kwargs)">
     <%def name="predefined_type_inner(name, type, initial_value, parse_method)">
         #[allow(unused_imports)]
         use app_units::Au;
@@ -15,6 +15,9 @@
             pub use values::computed::${type} as T;
         }
         #[inline] pub fn get_initial_value() -> computed_value::T { ${initial_value} }
+        % if initial_specified_value:
+        #[inline] pub fn get_initial_specified_value() -> SpecifiedValue { ${initial_specified_value} }
+        % endif
         #[allow(unused_variables)]
         #[inline] pub fn parse(context: &ParserContext, input: &mut Parser)
                                -> Result<SpecifiedValue, ()> {
diff --git a/components/style/properties/longhand/background.mako.rs b/components/style/properties/longhand/background.mako.rs
index 6aa537b269a..429731b8158 100644
--- a/components/style/properties/longhand/background.mako.rs
+++ b/components/style/properties/longhand/background.mako.rs
@@ -8,6 +8,7 @@
 
 ${helpers.predefined_type("background-color", "CSSColor",
     "::cssparser::Color::RGBA(::cssparser::RGBA::transparent())",
+    initial_specified_value="SpecifiedValue::transparent()",
     spec="https://drafts.csswg.org/css-backgrounds/#background-color",
     animatable=True, complex_color=True)}
 
diff --git a/components/style/properties/longhand/column.mako.rs b/components/style/properties/longhand/column.mako.rs
index f55524f5201..b3c782e5c2e 100644
--- a/components/style/properties/longhand/column.mako.rs
+++ b/components/style/properties/longhand/column.mako.rs
@@ -10,6 +10,7 @@
 ${helpers.predefined_type("column-width",
                           "length::LengthOrAuto",
                           "Either::Second(Auto)",
+                          initial_specified_value="Either::Second(Auto)",
                           parse_method="parse_non_negative_length",
                           extra_prefixes="moz",
                           animatable=False,
@@ -62,6 +63,11 @@ ${helpers.predefined_type("column-width",
         computed_value::T(None)
     }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue::Auto
+    }
+
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
@@ -146,6 +152,7 @@ ${helpers.single_keyword("column-fill", "auto balance", extra_prefixes="moz",
 // https://drafts.csswg.org/css-multicol-1/#crc
 ${helpers.predefined_type("column-rule-color", "CSSColor",
                           "::cssparser::Color::CurrentColor",
+                          initial_specified_value="specified::CSSColor::currentcolor()",
                           products="gecko", animatable=True, extra_prefixes="moz",
                           complex_color=True, need_clone=True,
                           spec="https://drafts.csswg.org/css-multicol/#propdef-column-rule-color")}
diff --git a/components/style/properties/longhand/font.mako.rs b/components/style/properties/longhand/font.mako.rs
index 4b05c50b970..37c467b242f 100644
--- a/components/style/properties/longhand/font.mako.rs
+++ b/components/style/properties/longhand/font.mako.rs
@@ -326,6 +326,11 @@ ${helpers.single_keyword("font-variant-caps",
         computed_value::T::Weight400  // normal
     }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue::Normal
+    }
+
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
@@ -407,6 +412,11 @@ ${helpers.single_keyword("font-variant-caps",
         Au::from_px(FONT_MEDIUM_PX)
     }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue(specified::LengthOrPercentage::Length(NoCalcLength::medium()))
+    }
+
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
@@ -502,6 +512,11 @@ ${helpers.single_keyword("font-variant-caps",
         computed_value::T::None
     }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue::None
+    }
+
     /// none | <number>
     pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
         use values::specified::Number;
@@ -750,6 +765,11 @@ ${helpers.single_keyword("font-variant-position",
         computed_value::T::Normal
     }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue::Normal
+    }
+
     pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
         if input.try(|input| input.expect_ident_matching("normal")).is_ok() {
             Ok(SpecifiedValue::Normal)
diff --git a/components/style/properties/longhand/inherited_text.mako.rs b/components/style/properties/longhand/inherited_text.mako.rs
index 60ca0ee5194..637c2776aa3 100644
--- a/components/style/properties/longhand/inherited_text.mako.rs
+++ b/components/style/properties/longhand/inherited_text.mako.rs
@@ -101,6 +101,11 @@
      #[inline]
     pub fn get_initial_value() -> computed_value::T { computed_value::T::Normal }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue::Normal
+    }
+
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
@@ -1031,6 +1036,7 @@ ${helpers.single_keyword("text-align-last",
 
 ${helpers.predefined_type("text-emphasis-color", "CSSColor",
                           "::cssparser::Color::CurrentColor",
+                          initial_specified_value="specified::CSSColor::currentcolor()",
                           products="gecko", animatable=True,
                           complex_color=True, need_clone=True,
                           spec="https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-color")}
@@ -1056,6 +1062,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "-webkit-text-stroke-color", "CSSColor",
     "CSSParserColor::CurrentColor",
+    initial_specified_value="specified::CSSColor::currentcolor()",
     products="gecko", animatable=True,
     complex_color=True, need_clone=True,
     spec="https://compat.spec.whatwg.org/#the-webkit-text-stroke-color")}
@@ -1066,7 +1073,7 @@ ${helpers.predefined_type(
     use std::fmt;
     use style_traits::ToCss;
     use values::HasViewportPercentage;
-    use values::specified::BorderWidth;
+    use values::specified::{BorderWidth, Length};
 
     pub type SpecifiedValue = BorderWidth;
 
@@ -1082,6 +1089,10 @@ ${helpers.predefined_type(
     #[inline] pub fn get_initial_value() -> computed_value::T {
         Au::from_px(0)
     }
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        BorderWidth::from_length(Length::zero())
+    }
 </%helpers:longhand>
 
 
diff --git a/components/style/properties/longhand/list.mako.rs b/components/style/properties/longhand/list.mako.rs
index 5f1bf103d7f..81ce62a32e1 100644
--- a/components/style/properties/longhand/list.mako.rs
+++ b/components/style/properties/longhand/list.mako.rs
@@ -38,7 +38,7 @@ ${helpers.single_keyword("list-style-type", """
     spec="https://drafts.csswg.org/css-lists/#propdef-list-style-type")}
 
 ${helpers.predefined_type("list-style-image", "UrlOrNone", "Either::Second(None_)",
-                          animatable=False,
+                          initial_specified_value="Either::Second(None_)", animatable=False,
                           spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image")}
 
 <%helpers:longhand name="quotes" animatable="False"
diff --git a/components/style/properties/longhand/outline.mako.rs b/components/style/properties/longhand/outline.mako.rs
index 8b2f51ef2ed..65be748c187 100644
--- a/components/style/properties/longhand/outline.mako.rs
+++ b/components/style/properties/longhand/outline.mako.rs
@@ -11,6 +11,7 @@
 
 // TODO(pcwalton): `invert`
 ${helpers.predefined_type("outline-color", "CSSColor", "::cssparser::Color::CurrentColor",
+                          initial_specified_value="specified::CSSColor::currentcolor()",
                           animatable=True, complex_color=True, need_clone=True,
                           spec="https://drafts.csswg.org/css-ui/#propdef-outline-color")}
 
@@ -39,6 +40,11 @@ ${helpers.predefined_type("outline-color", "CSSColor", "::cssparser::Color::Curr
         Either::Second(BorderStyle::none)
     }
 
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        Either::Second(BorderStyle::none)
+    }
+
     pub mod computed_value {
         pub type T = super::SpecifiedValue;
     }
@@ -88,7 +94,13 @@ ${helpers.predefined_type("outline-color", "CSSColor", "::cssparser::Color::Curr
         use app_units::Au;
         pub type T = Au;
     }
+
     pub use super::border_top_width::get_initial_value;
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue(specified::Length::NoCalc(specified::NoCalcLength::medium()))
+    }
+
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
diff --git a/components/style/properties/longhand/text.mako.rs b/components/style/properties/longhand/text.mako.rs
index 9b2a851bc6f..654eac072ae 100644
--- a/components/style/properties/longhand/text.mako.rs
+++ b/components/style/properties/longhand/text.mako.rs
@@ -169,6 +169,10 @@ ${helpers.single_keyword("unicode-bidi",
     #[inline] pub fn get_initial_value() -> computed_value::T {
         computed_value::none
     }
+    #[inline]
+    pub fn get_initial_specified_value() -> SpecifiedValue {
+        SpecifiedValue::empty()
+    }
     /// none | [ underline || overline || line-through || blink ]
     pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
         let mut result = SpecifiedValue::empty();
@@ -219,7 +223,8 @@ ${helpers.single_keyword("text-decoration-style",
 
 ${helpers.predefined_type(
     "text-decoration-color", "CSSColor",
-    "CSSParserColor::RGBA(RGBA::new(0, 0, 0, 255))",
+    "::cssparser::Color::CurrentColor",
+    initial_specified_value="specified::CSSColor::currentcolor()",
     complex_color=True,
     products="gecko",
     animatable=True,
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
index 8293622cbe5..97ef54845ab 100644
--- a/components/style/values/specified/length.rs
+++ b/components/style/values/specified/length.rs
@@ -344,6 +344,12 @@ impl NoCalcLength {
         *self == NoCalcLength::Absolute(Au(0))
     }
 
+    #[inline]
+    /// Returns a `medium` length.
+    pub fn medium() -> NoCalcLength {
+        NoCalcLength::Absolute(Au::from_px(FONT_MEDIUM_PX))
+    }
+
     /// Get an absolute length from a px value.
     #[inline]
     pub fn from_px(px_value: CSSFloat) -> NoCalcLength {
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 4dc93972554..7584ec7bee8 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -78,6 +78,27 @@ impl ToCss for CSSColor {
     }
 }
 
+impl CSSColor {
+    #[inline]
+    /// Returns currentcolor value.
+    pub fn currentcolor() -> CSSColor {
+        CSSColor {
+            parsed: cssparser::Color::CurrentColor,
+            authored: None,
+        }
+    }
+
+    #[inline]
+    /// Returns transparent value.
+    pub fn transparent() -> CSSColor {
+        CSSColor {
+            parsed: cssparser::Color::RGBA(cssparser::RGBA::transparent()),
+            // This should probably be "transparent", but maybe it doesn't matter.
+            authored: None,
+        }
+    }
+}
+
 #[derive(Clone, PartialEq, Debug)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 #[allow(missing_docs)]